import { ShieldCheck, Loader2, HeartHandshake, Users } from 'lucide-react';
import { Card, CardContent } from '@/components/ui/card';
import { Button } from '@/components/ui/button';
import { Avatar, AvatarFallback, AvatarImage } from '@/components/ui/avatar';
import {
  Tooltip,
  TooltipContent,
  TooltipProvider,
  TooltipTrigger,
} from '@/components/ui/tooltip';
import { Link } from 'react-router-dom';
import { nip19 } from 'nostr-tools';
import { useCurrentUser } from '@/hooks/useCurrentUser';
import { useAuthor } from '@/hooks/useAuthor';
import { useVouches, useVouchFor } from '@/hooks/useVouches';
import { useToast } from '@/hooks/useToast';
import { genUserName } from '@/lib/genUserName';
import { cn } from '@/lib/utils';

interface VouchCardProps {
  /** Provider coordinate `kind:pubkey:d`. */
  coord: string;
  /** Provider pubkey (to hide the button for the owner). */
  providerPubkey: string;
  /** Provider display name. */
  providerName: string;
  accentText?: string;
  accentBg?: string;
}

function VoucherAvatar({ pubkey }: { pubkey: string }) {
  const author = useAuthor(pubkey);
  const meta = author.data?.metadata;
  const name = meta?.name ?? genUserName(pubkey);
  const npub = nip19.npubEncode(pubkey);
  return (
    <TooltipProvider>
      <Tooltip>
        <TooltipTrigger asChild>
          <Link to={`/${npub}`}>
            <Avatar className="h-7 w-7 border border-white/10">
              <AvatarImage src={meta?.picture} alt={name} />
              <AvatarFallback className="text-[10px]">{name.slice(0, 2).toUpperCase()}</AvatarFallback>
            </Avatar>
          </Link>
        </TooltipTrigger>
        <TooltipContent>{name}</TooltipContent>
      </Tooltip>
    </TooltipProvider>
  );
}

/**
 * The community anti-fraud primitive. Skaters vouch for real providers; the
 * verdict is trust-weighted so fake profiles with only cold/fake vouches read as
 * "new / unvouched" while genuinely-known people surface as scene-verified.
 */
export function VouchCard({
  coord,
  providerPubkey,
  providerName,
  accentText = 'text-teal-400',
  accentBg = 'bg-teal-500 hover:bg-teal-600',
}: VouchCardProps) {
  const { user } = useCurrentUser();
  const { data, isLoading } = useVouches(coord);
  const { mutateAsync: vouch, isPending } = useVouchFor();
  const { toast } = useToast();

  const isOwner = user?.pubkey.toLowerCase() === providerPubkey.toLowerCase();

  // Trust tier from the trust-weighted score.
  const tier =
    data.trustedVouchers >= 3 || data.weightedScore >= 150
      ? 'verified'
      : data.count > 0
      ? 'vouched'
      : 'new';

  const handleVouch = async () => {
    try {
      await vouch({ coord, providerName, retract: data.viewerVouched });
      toast({
        title: data.viewerVouched ? 'Vouch removed' : 'Vouched!',
        description: data.viewerVouched
          ? `You no longer vouch for ${providerName}.`
          : `You vouched for ${providerName}. The scene trusts its own.`,
      });
    } catch (error) {
      toast({
        title: 'Could not vouch',
        description: error instanceof Error ? error.message : 'Please try again.',
        variant: 'destructive',
      });
    }
  };

  return (
    <Card className="border border-white/10 bg-black/60">
      <CardContent className="space-y-3 p-4">
        <div className="flex items-center justify-between gap-2">
          <p className="flex items-center gap-2 text-xs font-black uppercase tracking-widest text-gray-400">
            <HeartHandshake className={cn('h-4 w-4', accentText)} /> Scene Vouches
          </p>
          {tier === 'verified' && (
            <span className="inline-flex items-center gap-1 rounded-full bg-green-500/15 px-2 py-0.5 text-xs font-bold text-green-400">
              <ShieldCheck className="h-3 w-3" /> Scene-verified
            </span>
          )}
          {tier === 'vouched' && (
            <span className="inline-flex items-center gap-1 rounded-full bg-amber-500/15 px-2 py-0.5 text-xs font-bold text-amber-400">
              <Users className="h-3 w-3" /> Vouched
            </span>
          )}
          {tier === 'new' && (
            <span className="inline-flex items-center gap-1 rounded-full bg-white/5 px-2 py-0.5 text-xs font-bold text-gray-500">
              New · unvouched
            </span>
          )}
        </div>

        {isLoading ? (
          <p className="text-xs text-gray-500">Checking the scene…</p>
        ) : data.count === 0 ? (
          <p className="text-xs leading-relaxed text-gray-500">
            No vouches yet. Vouches from skaters in your circles are the best signal that
            someone's the real deal — not a random who wandered in.
          </p>
        ) : (
          <div className="space-y-2">
            <div className="flex items-center gap-1.5">
              <div className="flex -space-x-2">
                {data.vouchers.slice(0, 6).map((pk) => (
                  <VoucherAvatar key={pk} pubkey={pk} />
                ))}
              </div>
              <span className="text-sm font-bold text-gray-300">
                {data.count} vouch{data.count !== 1 ? 'es' : ''}
              </span>
            </div>
            {data.trustedVouchers > 0 && (
              <p className="text-xs text-green-500/80">
                🛡 {data.trustedVouchers} from skaters in your web of trust
              </p>
            )}
          </div>
        )}

        {user && !isOwner && (
          <Button
            type="button"
            onClick={handleVouch}
            disabled={isPending}
            variant={data.viewerVouched ? 'outline' : 'default'}
            className={cn(
              'w-full gap-2 font-bold',
              data.viewerVouched ? 'border-white/15 text-gray-300' : accentBg
            )}
          >
            {isPending ? (
              <Loader2 className="h-4 w-4 animate-spin" />
            ) : (
              <HeartHandshake className="h-4 w-4" />
            )}
            {data.viewerVouched ? 'Remove vouch' : `Vouch for ${providerName.split(' ')[0]}`}
          </Button>
        )}
        {isOwner && (
          <p className="text-center text-[11px] text-gray-600">
            Skaters who know your work can vouch for you here.
          </p>
        )}
      </CardContent>
    </Card>
  );
}